I was away on vacation for a few weeks came home and my fish is sick. He has white/grey on his fins and it seems he has lost some of them. His body is also curled over and he isn't swimming around much, stays in one place.

I have a 10G tank with filter, heater. The temp is always a steady 82. I'm pretty sure he got this from poor water quality.

I did a 75% water change, added some Aquarium salt. I know to keep his water very clean but is there any other advise anyone has?

thats fin rot, um I use melafix and am treating now. poor water quality is the number one culprit of fin rot there are other but dirty water is the most common. Bettafix and melafix are the same thing.

i've heard a lot of people (myself included) didn't get much help from melafix once the fin rot was really set in. It MAY help to heal but you'd need something stronger to cure it. I've had decent results with jungle fungus eliminator but it stains everything green. If the really clean water and aquarium salts don't help in a few days and it gets worse, i'd go with a med. you may want to do it soon, though, since it looks from those pics like it's getting really close to his body and once it hits the body, the fish is in more trouble and it gets harder to treat. good luck!

I have put in some Melafix.I have read that it is a bit strong of a medicine to use with a Betta though.
Should I use the Melafix and a bit of the salt for the next while?
I just don't want to cause him any more stress by irritating him with too much meds.

Also should I be doing really frequent water changes? Every 4th day or so at about 50%?

I think the ammonia in the tank was very high as I could smell it when I was cleaning out his tank. :( Pretty bad. I didn't change the water before I left for vacation and it didn't get changed by who was feeding him for me while I was away.

I feel so terrible for him and I hope he is not in pain.
He has always looked a little bit 'rough' since I bought him. Pale body and marks on his face. I just hope I am doing the right thing!

I will look into getting the Jungle Fungus Eliminator.. not sure they sell that where I live though.